How can I add a texture to a specific face?
Okay, I think I found a way (since unwrapping doesn't seem to work for me).


Select the part, go to edit mode, do a Ctrl+Tab and choose Face
Then select the face of the part I want to add texture to (there's a bunch of little triangles that need to be selected)
Next, assign a new material to that face, and deal with texture in Nodes.